Title:	STRONGER (Systematic Theoretical Review Of Nitride and silicide fuels Ground-state Energy Results)
DNr:	SNIC 2016/1-281
Project Type:	SNIC Medium Compute
Principal Investigator:	Janne Wallenius <janne@neutron.kth.se>
Affiliation:	Kungliga Tekniska högskolan
Duration:	2016-06-29 – 2017-01-01
Classification:	10304
Homepage:	http://neutron.kth.se/
Keywords:

Abstract

Accident tolerant fuels (ATF) are an essential part of the GEN IV nuclear reactor designs. By their very nature, they will improve the safety of these installations. Two of the main candidates for ATF are nitride and silicide compounds. Before being able to undergo a licensing process, their properties need to be determined, and until now, few experiments are available. Ab initio modelling can help reduce uncertainties on key parameters, such as the thermal conductivity or the swelling under irradiation. Research groups at the CEA, Los Alamos National Lab, ITU and many other universities have already joined KTH in this effort. However, at the beginning of the 2010’s, a problem of metastable states was revealed when dealing with strongly correlated materials such as nuclear fuels. Many schemes using or completing the conventional Density Functional Theory (DFT) have been suggested, and have to be applied. In this project, we propose to investigate nitride and sicilide fuels using a modified version of VASP, including the occupation matrix control scheme. Doing so, we can establish precisely the ground-state of these compounds, and determine reliably the macroscopic properties that are needed for licensing. The viability of these method has been successfully tested in UO2 (many publications) and in UN (JNM, 2016). Investigating the large array of fuel possibilities in a systematic and extensive way is a computationally expensive work that has to be done early, to guaranty the accuracy of future results. We will do it using our own compilation of VASP, using the DFT+U+OMC framework.